Traditional lightbulbs feature clear housings which do not modify the color of the produced light. These lightbulbs produce a somewhat harsh light that many find off putting. To counteract this displeasing effect, layers of diffusion material are frequently applied to lightbulbs. These diffusion layers soften the light and modify its characteristics. Building upon this idea, it is possible to produce light with desired characteristics by using various combinations of light and diffusion materials. For example, white light is produced by shining a blue light onto a layer of phosphoric material.
Although this method of light modification produces light with desired properties, a significant amount of the perceivable light is lost. This loss is due to the fact that a portion of the light is reflected off of the diffusion material and some of the radiant conversion is back not forward. Because some of the light is lost, a user must employ more powerful light sources to achieve a desired level of brightness. This practice wastes energy and costs user's money.
Therefore, the object of the present invention is to employ a mirror to redirect light which would otherwise be lost. The present invention uses an arrangement of components that enable light to pass through an aperture in a mirror. The aperture enables light to enter a diffuser, which splits the light into multiple beams, before it strikes a modifying substrate. Additionally, this aperture is sufficiently small that light is prevented from passing through in the opposite direction. Once the multiple beams of light strike the modifying substrate, a portion of the light is directed backwards. However, because of the mirror the light which would normally be lost is reflected back towards the modifying substrate. Using the diffuser to spread the source light, and the mirror to redirect wasted light, increases the efficiency of the present invention.
The method of use for the present invention employs a diffuser optical material with Gaussian profile that diffracts collimated blue laser beam (single wavelength) to produce multiple beams. These beams then strike an illuminate material (phosphor) substrate that is attuned to the wavelength of the blue laser. Thus converting the blue laser beams into white light. In addition to the illuminate material, the diffuser optical material is attuned to a specific light wavelength to provide resulting output pattern of beams (e.g., Gaussian profile). Furthermore, other wavelengths of light pass through the diffuser optical material unhindered.
The use of a diffractive optical element (DOE) creates multiple beams to prevent saturation of the illuminate material substrate by a single beam of light. However, a single beam could be used, and would also reflect back unconverted blue light as well as converted white light. A majority of the produced white is directed forward, while some is directed back. Additionally, some of the not fully converted blue laser beams that do not make it through the illuminate material or DOE are directed backwards. The mirror reflects the blue light forward again. Because the white light is a different wavelength it easily passes through the DOE and the illuminate material. In addition, any blue light that was not converted is also reflected back by the mirror through the DOE and converted to white light by the illuminate material substrate.